Added unit tests

Author: alan-null

Tests/Crypto.RSA.Tests.ps1

@@ -0,0 +1,43 @@
+Clear-Host
+Import-Module -Name Pester -Force
+Import-Module .\Crypto.RSA\Crypto.RSA.psm1 -Force
+
+Describe 'Crypto.RSA.Tests' {
+    Context "Keys generation" {
+        It "Generates public and private keys" {
+            $keys = New-KeyPair
+            $keys.public | Should -Not -BeNullOrEmpty
+            $keys.private | Should -Not -BeNullOrEmpty
+        }
+    }
+
+    Context "String encryption - happy path" {
+        $keys = New-KeyPair
+        $plain = "Crypto.RSA"
+
+        $encryptedText = Protect-String $plain $keys.public
+        $decryptedText = Unprotect-String $encryptedText $keys.private
+
+        It "Encrypted text is NOT the same as plain" {
+            $encryptedText | Should -Not -Be $plain
+        }
+        It "Decrypted text is the same as plain" {
+            $decryptedText | Should -Be $plain
+        }
+    }
+
+    Context "String encryption - incorrect private key" {
+        $keys = New-KeyPair
+        $incorrect_keys = New-KeyPair
+        $plain = "Crypto.RSA"
+        $encryptedText = Protect-String $plain $keys.public
+
+        It "Decrypted with valid key works" {
+            Unprotect-String $encryptedText $keys.private | Should -Be $plain
+        }
+
+        It "Decrypted with invalid key throws an exception" {
+            { Unprotect-String $encryptedText $incorrect_keys.private } | Should Throw "Cryptography_OAEPDecoding"
+        }
+    }
+}